title: Automatic prostate segmentation in cone-beam computed tomography images using rigid registration.
abstract: We propose to evaluate automatic three-dimensional gray-value rigid registration (RR) methods for prostate localization on cone-beam computed tomography (CBCT) scans. In total, 103 CBCT scans of 9 prostate patients have been analyzed. Each one was registered to the planning CT scan using different methods: (a) global RR, (b) pelvis bone structure RR, (c) bone RR refined by local soft-tissue RR using the CT clinical target volume (CTV) expanded with a 1, 3, 5, 8, 10, 12, 15 or 20-mm margin. To evaluate results, a radiation oncologist was asked to manually delineate the CTV on the CBCT scans. The Dice coefficients between each automatic CBCT segmentation - derived from the transformation of the manual CT segmentation - and the manual CBCT segmentation were calculated. Global or bone CT/CBCT RR has been shown to yield insufficient results in average. Local RR with an 8-mm margin around the CTV after bone RR was found to be the best candidate for systematically significantly improving prostate localization.
authors.forename: Christine
authors.initials: C
authors.lastname: Boydev
authors.forename: David
authors.initials: D
authors.lastname: Pasquier
authors.forename: Foued
authors.initials: F
authors.lastname: Derraz
authors.forename: Laurent
authors.initials: L
authors.lastname: Peyrodie
authors.forename: Abdelmalik
authors.initials: A
authors.lastname: Taleb-Ahmed
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Thiran
mesh_terms: D000465:Algorithms; D001842:Bone and Bones / Q000000981:diagnostic imaging; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D010388:Pelvis / Q000000981:diagnostic imaging; D011467:Prostate / Q000000981:diagnostic imaging*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods